Boxing a primitive using the constructor ("new Integer(4)") always
creates a distinct new boxed instance. That's rarely what you need,
and in fact all of those constructors have been deprecated in Java 9.
Using the static "valueOf" method instead ("Integer.valueOf(4)") can
give better performance by reusing existing instances. You no longer
get a unique boxed object, but generally that's OK.
This gives the WALA maintainers the option of doing future 1.4.5+
releases from of a pre-Gradle branch if these merged Gradle changes
turn out to be more disruptive than expected.
The Eclipse metadata files created in this way are not identical to
those that Buildship would create when importing into Eclipse. The
tests in com.ibm.wala.cast.java.test.JDTJava15IRTests and
com.ibm.wala.cast.java.test.JDTJavaIRTests seem to pass using either
the Gradle-generated or the Buildship-generated versions.
As an aside, if you generate these files using Gradle first and *then*
import using Buildship, you end up with metadata that is identical to
what you would have had if you'd only imported with
Buildship. (There's one irrelevant difference in an unimportant
"<comment>" element.) So Maven's tests should run fine under any
wacky mix of Gradle- and Buildship-generated Eclipse metadata files.
That being said, I recommend not mixing build systems. WALA can be
built using either Maven, Gradle, or Eclipse+Buildship, but you're
probably better off only using one of these in any given build tree.
A mixed tree *should* probably work, but I haven't tested it
thoroughly, and consider better to avoid doing.
Incidentally, if there are other Maven-preparation steps that we'd
like Gradle to automate for us, that can now be done easily by
creating more "prepareMavenBuild" Gradle tasks in other subprojects
and adding the appropriate dependencies. For example, it would be
trivial to use this to automate downloading "/tmp/DroidBench",
installing the Android SDK, etc.
We now download and verify checksums as a single task, rather than as
two separate tasks. This simplifies other task dependencies, since we
no longer have a checksum-verified "stamp" file separate from the
download itself. Unfortunately the combined task now has a
significant amount of repeated boilerplate. I'm hoping to refactor
that all out into a custom task class, but haven't yet figured out the
details:
<https://github.com/michel-kraemer/gradle-download-task/issues/108>.
We now also use ETags to be smarter about when a fresh download is or
is not actually needed. I think there are still opportunities for
improved caching here, but this is a step in the right direction.
A cleaned tree is now much closer to a pristine tree that has just
been checked out and never built. The only extra created files that
are left behind are ".gradle", "buildSrc/.gradle", and
"buildSrc/build".
I think these were previously not being compiled at all. Now, with
Buildship generating Eclipse ".project" settings automatically, these
are being processed. In general we don't care much about questionable
code in test data, though.
These settings files currently are generated with an initial timestamp
comment line, which is not something we'd want to track in version
control. Fortunately, the contents of these files are entirely
mundane, so there should be no problem with having Buildship generate
them anew each time a developer imports WALA into Eclipse as an
existing Gradle project.
Apparently Buildship generates these when one uses Import -> Existing
Gradle Project:
<https://discuss.gradle.org/t/buildship-eclipse-plug-in-multiproject-builds/24030/5>.
We can use the Gradle "eclipse" plugin if customizations are
necessary, but my impression is that the intent is to treat ".project"
and ".classpath" as generated files, not sources to be tracked in
source control.
I was confused about the differences among:
srcDir 'foo'
srcDirs ['foo']
srcDirs = ['foo']
As it turns out, the first two append to the set of source
directories, while the last replaces this set entirely. I generally
want replacement, since WALA's current directory layout never matches
Gradle's assumed defaults.
This gives the WALA maintainers the option of doing future 1.4.5+
releases from of a pre-Gradle branch if these merged Gradle changes
turn out to be more disruptive than expected.
The Eclipse metadata files created in this way are not identical to
those that Buildship would create when importing into Eclipse. The
tests in com.ibm.wala.cast.java.test.JDTJava15IRTests and
com.ibm.wala.cast.java.test.JDTJavaIRTests seem to pass using either
the Gradle-generated or the Buildship-generated versions.
As an aside, if you generate these files using Gradle first and *then*
import using Buildship, you end up with metadata that is identical to
what you would have had if you'd only imported with
Buildship. (There's one irrelevant difference in an unimportant
"<comment>" element.) So Maven's tests should run fine under any
wacky mix of Gradle- and Buildship-generated Eclipse metadata files.
That being said, I recommend not mixing build systems. WALA can be
built using either Maven, Gradle, or Eclipse+Buildship, but you're
probably better off only using one of these in any given build tree.
A mixed tree *should* probably work, but I haven't tested it
thoroughly, and consider better to avoid doing.
Incidentally, if there are other Maven-preparation steps that we'd
like Gradle to automate for us, that can now be done easily by
creating more "prepareMavenBuild" Gradle tasks in other subprojects
and adding the appropriate dependencies. For example, it would be
trivial to use this to automate downloading "/tmp/DroidBench",
installing the Android SDK, etc.
We now download and verify checksums as a single task, rather than as
two separate tasks. This simplifies other task dependencies, since we
no longer have a checksum-verified "stamp" file separate from the
download itself. Unfortunately the combined task now has a
significant amount of repeated boilerplate. I'm hoping to refactor
that all out into a custom task class, but haven't yet figured out the
details:
<https://github.com/michel-kraemer/gradle-download-task/issues/108>.
We now also use ETags to be smarter about when a fresh download is or
is not actually needed. I think there are still opportunities for
improved caching here, but this is a step in the right direction.
A cleaned tree is now much closer to a pristine tree that has just
been checked out and never built. The only extra created files that
are left behind are ".gradle", "buildSrc/.gradle", and
"buildSrc/build".
I think these were previously not being compiled at all. Now, with
Buildship generating Eclipse ".project" settings automatically, these
are being processed. In general we don't care much about questionable
code in test data, though.
These settings files currently are generated with an initial timestamp
comment line, which is not something we'd want to track in version
control. Fortunately, the contents of these files are entirely
mundane, so there should be no problem with having Buildship generate
them anew each time a developer imports WALA into Eclipse as an
existing Gradle project.
Apparently Buildship generates these when one uses Import -> Existing
Gradle Project:
<https://discuss.gradle.org/t/buildship-eclipse-plug-in-multiproject-builds/24030/5>.
We can use the Gradle "eclipse" plugin if customizations are
necessary, but my impression is that the intent is to treat ".project"
and ".classpath" as generated files, not sources to be tracked in
source control.
I was confused about the differences among:
srcDir 'foo'
srcDirs ['foo']
srcDirs = ['foo']
As it turns out, the first two append to the set of source
directories, while the last replaces this set entirely. I generally
want replacement, since WALA's current directory layout never matches
Gradle's assumed defaults.
Julian Dolby assures me that WALA is now supposed to be using Java 8
everywhere. This covers nearly all remaining places that I can find
where an earlier Java version was still being used. (The few
exceptions are places where switching to Java 8 causes test failures.
I'll address those separately, probably by reaching out to the WALA
maintainers for help.)
Manu Sridharan
Ben Liblit